Web Services and HL7v3 in IHE profiles Vassil Peytchev Epic

Introduction Web Services Overview Web Services in IHE – Why and How HL7 Version 3 HL7 Version 3 in IHE – Why and How First Steps

Web Services Overview In the beginning there was the Internet (TCP/UDP + IP) –Then came the Web (http + html) –Then XML + DTD –Then XML Namespaces + XML Schema –Then SOAP + UDDI + WSDL –… and there were Web Services!

What are Web Services (W3C) The programmatic interfaces used for application to application communication over the World Wide Web (W3C) Web Services provide a standard means of interoperating between different software applications SOAP-based messaging infrastructure and transport mechanism

Web Services Building Blocks A number of standards –SOAP (1.1, 1.2) –WSDL (1.1) –WS-Addressing –WS-Security –WS-Secure Conversation –WS-Policy –WS-Reliable Messaging –XOP –MTOM How do we navigate?

Web Services Building Blocks Metadata Foundation Messaging Assurances Infrastructure and Profiles WS-Transfer WS- Enumeration WS-Eventing SOAP WS- Addressing MTOM XML Infoset XML 1.0 XML Namespaces MIMESOAP/HTTP SOAP/UDP XML Schema WS-Security WS-Trust WS-Secure Conversation WSDL WS-Policy WS-Security Policy WS- Discovery WS-Metadata Exchange WS-Reliable Messaging WS- Coordination WS-Atomic Transaction WS-Business Activity WS- Federation WS- Management WS-Devices Profile Community work Standards Track Standard Color Code:

Web Services-Interoperability Organization (WS-I) An open industry organization chartered to promote Web services interoperability across platforms, operating systems, and programming languages. Delivers practical guidance, best practices and resources for developing interoperable Web services solutions.

WS-I Profiles Current: –Basic Profile Simple Soap Binding Profile 1.0 (SOAP WSDL UDDI 2.x) –Basic Security Profile 1.0 (WS-Security 1.0) Working on: –Basic Profile 1.2 (WS-Addressing) –Basic Security Profile 1.1 (WS-Security 1.1) –Basic Profile 2.0 (MTOM, XOP, SOAP 1.2) –Reliable Secure Profile (WS-Reliable Messaging, WS- Secure Conversation) Interoperability Testing Tools (C# and Java versions)

Why Web Services in IHE Original focus: Interoperability in the enterprise Expanded focus: Cross-enterprise interoperability Web Services can provide interoperable transport and messaging infrastructure for IHE transactions –Improve ease of implementation –Common transaction infrastructure –Layered security and reliability –Extensibility –Scalability

Ease of Implementation Web Services support in major development frameworks –Apache Axis2 –Eclipse Web Standard Tools subproject –IBM WebSphere Business Integration Adapter for Web services –Microsoft Communication Foundation (.NET 3.0) –Sun JAX-WS and WSIT

Using Web Services In IHE Transactions Appendix V –Explains how to specify web services for IHE transactions –Compatible with the HL7 V3 WS Profile –Refined based on last year’s experiences –Out for 2 nd public comment

HL7 Version 3 The Next Generation of HL7 Specifications –Based on a Reference Information Model (RIM) –Message design on an abstract level – independent of interchange format –Current interchange format is XML

Why HL7 Version 3 Clinical Content –CDA –CCD –Patient Care Messages XML Formatting Well Suited for Web Services Local Mandates/Investment in HL7 V3 Infrastructure

Using HL7 Version 3 in IHE Transactions Follow HL7 Development Model –Constrain existing messages –Express constraints via models –Use existing HL7 schemas and artifacts

Implementing HL7 V3 Transactions Model Structure –Need to retain link to underlying model (XML schema is not enough) XML –XML Schema validation is necessary, but no sufficient –XPath or Schematron rules can enforce IHE compliance

First Steps Profiles Using HL7 Messages and Web Services –PIX/PDQ HL7 V3 –Query for Existing Data (QED) Other Profiles Using Web Services –XDS.b –RFD –XCA Feedback –All profiles are about to be published for public comments –Please send comments

Questions? Vassil Peytchev